Trailer system and method for inspecting vehicle by radiation imaging of vehicle through trailer system

ABSTRACT

The present invention relates to a trailer system, and particularly to a self-driving trailer system for a radiation imaging inspection system and a method for inspecting a vehicle by radiation imaging of a vehicle through the trailer system. The self-driving trailer system comprises two trailers symmetrical in structure. Each of the trailers comprises a driving device, running wheels, a trailer body, a carrying device, a lift cylinder, a balance wheel, and two pairs of guide wheels. The driving device, the running wheels, and the balance wheel are coupled with the trailer body. The carrying device is coupled with the trailer body through the lift cylinder. A front carrying arm and a rear carrying arm can clamp front wheels of a vehicle under inspection, and move upwards and downwards by the lift cylinder. The trailer system according to the present invention is smooth and reliable in operation and simple in structure, and is applicable to different diameters of wheels of container lorries under inspection and is convenient in operation.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a trailer system, and particularly to a trailer system for a radiation imaging inspection system.

2. Description of the Related Art

With the increasingly wide application of large containerized cargo inspection systems, it has been more and more concerned whether a vehicle under inspection can pass through a scanning passage quickly and safely during inspection since the quick and safe passing of the vehicle is a key factor to vehicle passing rate and application of the system. Conventionally, special traction devices for the inspection systems comprise a flat car, a plate conveyer, small traction vehicles, and the like.

For example, an inspection system has an inspection passage of a length of 60 m and two portions located outside respective ends of the inspection passage and each having a length of 40 m. A traction system for the inspection system is very huge so that the system occupies a large area for civil construction. Further, it is high in cost for manufacturing and mounting components of the system, and is difficult in maintenance. In addition, the system can not randomly be used for inspection at a place different from a spot where the system is located.

Another existing inspection system is configured to have three underground traction vehicles for cycle traction. However, action of the traction vehicles between the ground and the underground makes the system complicated. In addition, when the traction vehicle draws a container car, front wheel of the container car may slip, so that the container car probably drops forwards or rearwards from the traction vehicle to impact and damage the container car and the inspection system.

Chinese Patent Application CN 1324751 A filed by the present applicant discloses an automatic flat car for a stationary container inspection system. In inspection, a vehicle under inspection completely moves onto the automatic flat car. The flat car is equipped with longitudinal and transverse travel mechanisms so that it can moves on a rectangular rail to cycle or reciprocate. The flat car transports vehicles under inspection to pass through a scanning passage. In order to ensure passing rate of vehicles under inspection in the system, one system is generally provided with one or a plurality of automatic flat cars. The automatic flat car bears whole weight (including cargo) of a vehicle under inspection. Due to this, it is huge, complicated in structure, excessive in number of attachments, large in consumption of energy, great in occupied area, and high in manufacturing cost and maintenance cost.

Chinese Patent Application CN 1324750 A filed by the present applicant discloses a plate link chain conveyor for a stationary container inspection system. The conveyor comprises a driving device, a front driving wheel device, a frame, a rear tensioner, and the like. The conveyor is suitable for transporting containers or pelletized cargo, but is inapplicable to traction of trucks under inspection and especially a container lorry with cargo.

Chinese Patent Application CN 1607135A filed by the present applicant discloses a trailer of a trailer system for radiation imaging. A driving device for the trailer includes winches disposed at both ends of an inspection passage, respectively. The winches draw the trailer to pass through the inspection passage by means of steel cable. In inspection, the trailer is locked, and front wheels of a vehicle under inspection move onto the trailer and stop at positioning sockets of the trailer to be positioned. However, the positioning sockets can only abut against the wheels from rear sides of the wheels when the trailer moves, but can not prevent the vehicle under inspection from swinging back and forth because of inertia force generated by starting and stopping the trailer. In addition, in inspection, if rails for the trailer are slightly uneven, speed of the trailer and the vehicle under inspection varies. A design height of the trailer will affect usage of the trailer to a great extent because of limitations of structure. When a container lorry moves onto or leaves the trailer, the trailer sometimes scratches parts of the container lorry such as a chassis and an oil tank to harm the container lorry under inspection. Moreover, when the winch drives the trailer to start and stop, it generates a great impact on the steel cable so that the speed of the vehicle under inspection varies. As a result, image quality is adversely affected. Therefore, a radiation inspection system to which the trailer is applied is poor in reliability, the image quality of the image obtained by the system is unstable, and the system requires high-quality civil construction.

Therefore, the conventional inspection systems has a huge traction system, is complicated in structure, excessive in appurtenant facilities, and large in energy consumption.

SUMMARY OF THE INVENTION

In order to overcome the above defects existing in the prior art, it is an object of the present invention to provide a trailer system which is stable and reliable in operation, simple in structure, and convenient in usage.

In accordance with an aspect of the present application, there is provided a trailer system comprising two trailers disposed opposite to each other, each of the two trailers comprising a trailer body; a carrying device disposed on a side of the trailer body facing a region between the two trailers for lifting and lowering an object and supporting the object during carrying the object by the trailer.

According to another aspect of the present application, there is provided a method for inspecting a vehicle by radiation imaging of the vehicle in a scanning passage through a trailer system. The trailer system comprises two trailers disposed opposite to each other, each of the two trailers comprising a trailer body; and a carrying device disposed on a side of the trailer body facing a region between the two trailers for lifting and lowering a front wheel of the vehicle and supporting the front wheel during carrying the vehicle by the trailer. The method comprises the steps of: lifting the front wheels of the vehicle under inspection by means of the carrying devices of the two trailers, and inspecting the object by radiation scanning of the vehicle while the trailers move.

In accordance with a further aspect of the present application, there is provided a self-driving trailer system comprising two trailers symmetrical in structure, each of the trailers comprising a driving device, running wheels, a trailer body, a carrying device, a lift cylinder, a balance wheel, and two pairs of guide wheels. The driving device, the running wheels, and the balance wheel are coupled with the trailer body. The balance wheel is located at a side of the trailer body outside the running wheels. The carrying device is coupled with the trailer body through the lift cylinder. One pair guide wheels of the two pairs of guide wheels are mounted at a front end of the trailer body and the other pair guide wheels are mounted at a rear end of the trailer body so as to guide the trailer when the trailer runs.

Preferably, the carrying device comprises: a base disposed to the trailer body to be movable upwards and downwards, a front carrying arm assembly and a rear carrying arm assembly coupled with the base to support the object during lifting and lowering the object and carrying the object, wherein the rear carrying arm assembly is substantially horizontally movable and connected with the base.

Preferably, the carrying device comprises: a rear carrying arm assembly moving cylinder for substantially horizontally moving the rear carrying arm assembly.

Preferably, the front carrying arm assembly comprises: a cylinder, a rotary arm, a shaft, a front carrying arm and a sensor disposed on the front carrying arm. The rotary arm is coupled with the shaft through a key, and the shaft is coupled with the front carrying arm through a key. In operation, the cylinder drives the rotary arm to rotate so that the shaft and the front carrying arm are driven to rotate. In operation, the front carrying arm is spread to be positioned at an angle of 90 degrees with respect to the trailer body, and the trailer moves towards a container lorry stopping at an entrance of a scanning passage. When the front carrying arm touches a front wheel of the container lorry under inspection, the sensor sends a signal so that the trailer stops and an addressing action is completed.

Preferably, the rear carrying arm similar to the front carrying arm in configuration is coupled with the base and comprises a cylinder, a rotary arm, a shaft, and a rear carrying arm. The rotary arm is coupled with the shaft through a key, and the shaft is coupled with the rear carrying arm through a key. In operation, the cylinder drives the rotary arm to rotate so that the shaft and the rear carrying arm are driven to rotate, and thus the rear carrying arm is positioned in an operation state or a retracted state.

In operation, the rear carrying arm is positioned at an angle of 90 degrees with respect to the trailer body. The difference between the rear carrying arm and the front carrying arm is that the rear carrying arm and the front carrying arm rotate in opposite directions, respectively, in order that the rear carrying arm and the front carrying arm are positioned in respective operation states. The front carrying arm and the rear carrying arm abut against the front wheel of the container lorry from a front side and a rear side of the wheel, respectively. The rear carrying arm rotates to be positioned at an angle of 90 degrees with respect to the trailer body after the addressing action is completed by the front carrying arm. The rear carrying arm not only can rotate, but also can slide horizontally. A rear carrying arm assembly moving cylinder has a cylinder body connected to the base and a piston rod connected to the rear carrying arm assembly. The piston rod extends and retracts to drive the rear carrying arm assembly to generally horizontally move along base slide grooves disposed in the base. The trailer system can automatically judge whether the front carrying arm and the rear carrying arm have already abutted against the front wheel of the container lorry by setting an operation pressure of the rear carrying arm assembly moving cylinder. If the system determines that the front carrying arm and the rear carrying arm have already abutted against the front wheel, the system sends a signal to stop movement of the piston rod of the rear carrying arm assembly moving cylinder, and the trailer continues the following operations. The front carrying arm and the rear carrying arm are now parallel to each other. Up to now, the trailer has completed the addressing action and the correcting action.

Preferably, the two base slide grooves are disposed in the base of the carrying device, and the rear carrying arm assembly can move horizontally along the base slide grooves by the rear carrying arm assembly moving cylinder.

Preferably, two trailer body slide grooves are disposed in the trailer body and the carrying device can be lifted and lowered by the lift cylinder along the trailer body slide grooves.

Preferably, the system further comprises a self balancing system embodied by a balance wheel. With the balance wheel, frictional force between the trailers and rails for the trailers increases so that weight of the trailers can decrease. The balance wheel, and the front carrying arm and the rear carrying arm are disposed on opposite sides of the running wheels, respectively. In operation, the balance wheel rolls along a groove-shaped track fixed to a foundation for the system. The balance wheel is used to balance the trailer subjected to an overturning moment generated by weight of the container lorry under inspection and the trailer in operation. In addition, a normal force applied by the running wheels of the trailers to the rails for the trailers increases because of the groove-shaped track fixed to the foundation so that the frictional force between the running wheels and the rails increases. As a result, an available power of the driving device of the trailer increases so as to avoid adding weight to the trailer for improving the frictional force, and so as to decrease total weight of the trailer system.

The lift cylinder is used to drive the carrying device to move upwards along the slide grooves formed in the trailer body so that the front wheels of the container lorry under inspection are spaced apart from the ground. The container lorry under inspection is pulled by the trailers to pass through the scanning passage.

According to a still further aspect of the present invention, there is provided an inspection method by radiation imaging of a vehicle by using the self-driving trailer system. The inspection method comprises the following steps:

spreading the front carrying arm to be positioned at an angle of 90 degrees with respect of the trailer body;

moving the trailer and thus the front carrying arm towards the vehicle under inspection, sending a control signal by the sensor when the front carrying arm touches a front wheel of the vehicle under inspection, and stopping the trailer so that an addressing action is completed;

rotating the rear carrying arm to be positioned at an angle of 90 degrees with respect to the trailer body, and horizontally moving the rear carrying arm along the base by the rear carrying arm assembly moving cylinder so that the front carrying arm and the rear carrying arm abut against the front wheel of the vehicle under inspection;

judging, with the trailer system, whether the front carrying arm and the rear carrying arm have clamped the front wheel of the vehicle under inspection at a predetermined clamping force by setting an operation pressure of the rear carrying arm assembly moving cylinder, and sending a signal by the trailer system to stop movement of the piston rod of the rear carrying arm assembly moving cylinder if the system determines that the front carrying arm and the rear carrying arm have clamped the front wheel of the vehicle at the predetermined clamping force;

lifting the carrying device by the lift cylinder so that the front wheel of the vehicle under inspection is spaced apart from the ground, and pulling the vehicle by means of the driving device so that the vehicle is scanned;

lowering the carrying device by the lift cylinder so that the vehicle moves downwards to the ground, after the scanning is completed;

rotating the front carrying arm and the rear carrying arm to be parallel to the passage or to be positioned at an angle of zero degree with respect to the trailer body, and driving the vehicle away from the scanning passage;

moving the trailer toward the entrance of the passage by the driving device, wherein after the front carrying arm and the rear carrying arm rotate to be positioned parallel to the passage or to be positioned at the angle of zero degree with respect to the trailer body, it is not necessary for the trailer to wait until the vehicle leaves the passage and the trailer may move toward the entrance of the passage immediately after the front carrying arm and the rear carrying arm rotate to be positioned parallel to the passage;

rotating the front carrying arm by 90 degrees to be perpendicular to the scanning passage or the trailer body after determining that the vehicle has left the passage and at the same time the trailer continues the moving towards the entrance of the passage;

sending a control signal by the sensor when the front carrying arm touches a front wheel of another vehicle under inspection, and stopping the trailer so that one scanning process is completed, and beginning the next scanning cycle.

Since the front carrying arm and the rear carrying arm can rotate and the rear carrying arm assembly can be translated, it is not necessary for a position of a container lorry under inspection stopping at the entrance of the scanning passage to be very accurate, but the trailer itself looks for and determines a position of a wheel of the container lorry stopping at the entrance. Therefore, accuracy with which a driver stops a container lorry can be lower and operation time of the system for scanning each vehicle can be decreased. In addition, a scanning cycle process can be simplified and the trailer can be applied to different diameters of wheels of vehicles under inspection so as to enlarge applications of the system. Furthermore, since the lift cylinder is used, it is not necessary for a container lorry to be driven onto or away from a trailer so that there is no risk for a chassis of the vehicle to be scraped. As a result, the system is safe and reliable.

The trailer system is smooth and stable in operation, stable in imaging quality, simple in structure and convenient in usage compared with a conventional system. Since the front carrying arm assembly and the rear carrying arm assembly can rotate, it is not necessary for a position of a container lorry under inspection stopping at the entrance of the scanning passage to be very accurate, but the trailer itself looks for and determines a position of the container lorry stopping at the entrance. Therefore, accuracy with which a driver stops a container lorry can be lower and operation time of the system for scanning each vehicle can be decreased. In addition, a scanning cycle process can be simplified, and only two trailers are needed to reciprocate. In addition, since the rear carrying arm assembly can be translated, the system is suitable for different diameters of container lorries under inspection. Furthermore, the frictional force increases and the weight of the system decreases because of the balance wheel.

BRIEF DESCRIPTION OF THE DRAWINGS

These and/or other aspects and advantages of the present invention will become apparent and more readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawing.

FIG. 1 is a schematic view showing a scanning system to which a trailer system according to the present invention is applied.

FIG. 2 is a schematic front view showing a trailer according to the present invention.

FIG. 3 is a schematic top view showing the trailer according to the present invention.

FIG. 4 is a schematic sectional view of FIG. 2.

FIG. 5 is a schematic view showing guide wheels of the trailer

FIG. 6 is a schematic front view showing a carrying device of the trailer.

FIG. 7 is a schematic top view showing the carrying device of the trailer.

DETAILED DESCRIPTION OF THE EMBODIMENTS

The embodiments are described below in order to explain the present invention, but do not pose a limitation on the scope of the invention.

FIG. 1 shows a radiation inspection system to which a self-driving system according to the present invention is applied. The self-driving system mainly comprises two trailers 1 and 2 symmetrical in structure. Hereinafter, only one trailer will be described in detail since the trailers 1 and 2 are symmetrical. The trailers 1 and 2 are disposed on both sides of a scanning passage, respectively, and are used to draw front wheels of a container lorry, respectively. In addition, the system is equipped with rails 3, cable drag chains for dragging electrical cables 4, an electrical controller (not shown), a concrete foundation (not shown), and the like. The trailers are driven to move back and forth along the rails through the electrical cables. The cable drag chains 4 are arranged along the respective rails. When the trailers operate, the cable traction chains 4 and thus the cables are reeled up or out with the movement of the trailers to protect the cables between the trailers and the controller. The traction chains 4 do not drive the trailers to move back and forth. The electrical controller is arranged in a controlling chamber for monitoring and controlling operation of all electromechanical components of the trailer system during inspection.

FIGS. 2 through 4 are a front view, a top view, and a sectional view of the trailer of the self-driving trailer system according to the preset invention. Each of the two trailers 1 and 2 comprises a trailer body 7; a carrying device 8 disposed on a side of the trailer body 7 facing a region between the two trailers (that is, a side facing a center of the scanning passage) for lifting and lowering an object (for example, an object or a vehicle under inspection) and supporting the object during carrying the object by the trailer. Each of the two trailers 1 and 2 may comprise a balance device disposed on the other side of the trailer body opposite to the side for balancing the trailer body 7 when the carrying device 8 lifts and lowers and carries the object. The balance device may comprise any appropriate balance devices such as a counter weight, balance wheel 10 (to be described later), or those known to the art.

In another embodiment, a trailer system of the present invention comprises two trailers 1 and 2 disposed opposite to each other, each of the two trailers comprising a trailer body; and a carrying device 8 disposed on a side of the trailer body facing a region between the two trailers 1 and 2 for lifting and lowering a front wheel of a vehicle and supporting the front wheel during carrying the vehicle by the trailers 1 and 2. A method for inspecting a vehicle by radiation imaging of the vehicle in a scanning passage through the above trailer system comprises steps of: lifting front wheels of the vehicle under inspection by means of the carrying devices 8 of the two trailers 1 and 2, and inspecting the vehicle by radiation scanning of the vehicle while the trailers move.

In the embodiments shown in FIGS. 2 through 4, the trailer comprises a driving device 5, running wheels 6, a trailer body 7, a carrying device 8, a lift cylinder 9, a balance wheel 10, and two pairs of guide wheels 11. The driving device 5, the running wheels 6, and the balance wheel 10 are coupled with the trailer body 7. The carrying device 8 is coupled with the trailer body 7 through the lift cylinder 9. The lift cylinder 9 is coupled with the trailer body 7 through a bolt. The driving device 5 drives the running wheels 6 to move so that the trailer body 7 moves along the rail together with the carrying device 8, the lift cylinder 9, the balance wheel 10, the guide wheels 11, and the other components. Two pairs of guide wheels 11 are arranged at a front end and a rear end of the trailer body 7, respectively, and two wheels 11 of each pair of guide wheels 11 are disposed on both sides of the rail 3 as shown in FIGS. 2, 3, and 5. The guide wheels 11 are used to guide the running wheels 6 to move along the rail 3 when the trailer runs. The guide wheels 3 roll along both side surfaces of the rail 3 because of frictional force applied to the guide wheels 3 when the guide wheels 1 contact the rail 3. As a result, running resistance to the trailer decreases.

Alternatively, each of the trailers 1 and 2 may be driven to move by winches (not shown) respectively disposed at an entrance and an exit of the scanning passage through steel cables, or by other means known to the art.

Slide grooves 7-1 and 7-2 are disposed in the trailer body 7 so that the lift cylinder 9 can drive the carrying device 8 move upwards and downwards along the slide grooves. It will be appreciated by those skilled in the art that the slide grooves 7-1 and 7-2 suffice for the trailer so long as the carrying device can move up and down along the slide grooves 7-1 and 7-2 in spite of positions and shapes of the slide grooves 7-1 and 7-2.

In addition, two groove-shaped tracks □not shown□ are disposed in the concrete foundation or a ground civil foundation or is fixed on both sides of the passage, respectively, and the two balance wheels 10 are disposed on a side of the trailer opposite to the carrying device 8 and are located in the corresponding groove-shaped track. In operation, the balance wheels 10 roll along the groove-shaped track fixed to the concrete foundation or the ground civil foundation, as shown in FIGS. 3 and 4.

FIGS. 4 and 6 are a front view and a top view illustrating the carrying device 8. As shown in FIGS. 4 and 6, the carrying device 8 mainly comprises: a base 8-1, a front carrying arm assembly 8-2 and a rear carrying arm assembly 8-3, a rear carrying arm assembly moving cylinder 8-4, and two sliders 8-5 and 8-6. Slide grooves 8-1-1 and 8-1-2 are disposed in the base 8-1. Like the slide grooves 7-1 and 7-2, the slide grooves 8-1-1 and 8-1-2 suffice for the trailer so long as the rear carrying arm assembly 8-3 can move leftward and rightward along the slide grooves 8-1-1 and 8-1-2 in spite of positions and shapes of the slide grooves 8-1-1 and 8-1-2.

The lift cylinder 9 can drive the carrying device 8 to move upwards and downwards along the trailer body so that front wheels of a container lorry can be spaced apart from the ground or be return to the ground. Specifically, the lift cylinder 9 drives the sliders 8-5 and 8-6 of the carrying device 8 move upwards and downwards along the slide grooves 7-1 and 7-2. In addition, engagement of the slider 8-5 and the slide groove 7-1 may constrain swings of the carrying device 8 around a first axis parallel to a moving direction of the trailer and around a second axis which is perpendicular to the first axis and which is vertical during upward and downward movement of the carrying device 8, and engagement of the slider 8-6 and the slide groove 7-2 may constrain swing of the carrying device 8 around a third axis which is perpendicular to the first axis and the second axis and which is horizontal during upward and downward movement of the carrying device 8.

Prior to scanning a container lorry, the lift cylinders 9 of the two trailers lift the carrying devices 8 so that front wheels of the container lorry are spaced apart from the ground. The driving devices 5 drive the respective trailers to pull the container lorry to pass through the scanning passage. After the scanning is completed, the lift cylinders 9 drive the carrying devices 8 to move downwards. As a result, the front wheels of the container lorry moves downwards to the ground. Then, the front carrying arm assemblies 8-2 and the rear carrying arm assemblies 8-3 are spread. A driver gets on the container lorry and drives the container lorry away from the scanning passage.

In the carrying device 8, the front carrying arm assembly 8-2 is coupled with the base 8-1 and comprise a cylinder 8-2-1, a rotary arm 8-2-2, a shaft 8-2-3, a front carrying arm 8-2-4 and a sensor 8-2-5 disposed on the front carrying arm. The cylinder 8-2-1 of the front carrying arm assembly 8-2 has a cylinder body rotatably fixed to the base 8-1 with a hinge and a piston rod rotatably connected to one end of the rotary arm 8-2-2 with a hinge. The other end of the rotary arm 8-2-2 and the front carrying arm 8-2-4 are connected with the base 8-1 through the shaft 8-2-3. The sensor 8-2-5 is mounted on the front carrying arm 8-2-4.

In operation, the cylinder 8-2-1 drives the rotary arm 8-2-2 to rotate around the shaft 8-2-3. The rotary arm 8-2-2 is coupled with the shaft 8-2-3 through a key, and the shaft 8-2-3 is coupled with the front carrying arm 8-2-4 through a key. Therefore, the cylinder 8-2-1 can drive the rotary arm 8-2-2 to rotate so that the rotary arm 8-2-2 drives the shaft 8-2-3 and the front carrying arm 8-2-4 to rotate. In operation, the front carrying arm 8-2-4 is spread to be positioned at an angle of 90 degrees with respect to the trailer body, and the trailer moves towards a container lorry stopping at the entrance of the scanning passage. When the front carrying arm 8-2-4 touches a front wheel of the container lorry under inspection, the sensor 8-2-3 sends a signal so that the trailer stops and an addressing action is completed.

Of course, the rotary arm 8-2-2 can be coupled with the shaft 8-2-3 in other manners in lieu of the key connection, and the shaft 8-2-3 can be coupled with the front carrying arm 8-2-4 in other manners in lieu of the key connection.

Similar to the front carrying arm assembly 8-2, the rear carrying arm assembly 8-3 is coupled with the base 8-1 and comprises a cylinder 8-3-1, a rotary arm 8-3-2, a shaft 8-3-3, and a rear carrying arm 8-3-4. In operation, the cylinder 8-3-1 drives the rotary arm 8-3-2 to rotate around the shaft 8-3-3. The rotary arm 8-3-2 is coupled with the shaft 8-3-3 through a key, and the shaft 8-3-3 is coupled with the rear carrying arm 8-3-4 through a key. Therefore, the cylinder 8-3-1 can drive the rotary arm 8-3-2 to rotate so that the rotary arm 8-3-2 drives the shaft 8-3-3 and the rear carrying arm 8-3-4 to rotate, and thus the rear carrying arm 8-3-4 is positioned in an operation state or a retracted state. In operation, the rear carrying arm 8-3-4 is positioned at an angle of 90 degrees with respect to the trailer body. The difference between the rear carrying arm and the front carrying arm is that the rear carrying arm and the front carrying arm rotate in opposite directions, respectively, in order that the rear carrying arm and the front carrying arm are positioned in respective operation states. The front carrying arm and the rear carrying arm abut against the front wheel of the container lorry from a front side and a rear side of the wheel, respectively. The rear carrying arm 8-3-4 rotate to be positioned at an angle of 90 degrees with respect to the trailer body after the addressing action is completed by the front carrying arm. The rear carrying arm 8-3-4 can not only rotate, but also can slide horizontally.

FIG. 3 is a view illustrating positions of the front carrying arm and the rear carrying arm positioned at an operation state and a non-operation state, in which imaginary lines indicate the non-operation state in which the front carrying arm and the rear carrying arm are parallel to the scanning passage or the trailer body, solid lines indicate the non-operation state in which the front carrying arm and the rear carrying arm are perpendicular to the passage or the trailer body, and arrows indicate moving directions of the front carrying arm and the rear carrying arm, respectively.

The rear carrying arm assembly moving cylinder 8-4 has a cylinder body connected to the base 8-1 and a piston rod connected to the rear carrying arm assembly 8-3. The piston rod extends and retracts to drive the rear carrying arm assembly 8-3 to generally horizontally move along slide grooves 8-1-1 and 8-1-2 disposed in the base 8-1. The trailer system can automatically judge whether the front carrying arm and the rear carrying arm have already clamped the front wheel of the container lorry at a predetermined clamping force by setting an operation pressure of the rear carrying arm assembly moving cylinder 8-4. If the trailer system determines that the front carrying arm and the rear carrying arm have already clamped the front wheel at the predetermined clamping force, the trailer system sends a signal to stop movement of the piston rod of the rear carrying arm assembly moving cylinder, and the trailer continues the following operations. The front carrying arm and the rear carrying arm are now parallel to each other. Up till now, the trailer has completed the addressing action and the correcting action.

After the above addressing and correction actions are completed, the lift cylinders 9 of the two trailers drive the respective carrying devices 8 to move upwards along the slide grooves 7-1 and 7-2 disposed in the trailer bodies 7, so that the front wheels of the container lorries are spaced apart from the ground. The driving devices 5 drive the respective trailers to pull the container lorry so that the container lorry passes through the scanning passage.

The rear carrying arm assembly moving cylinder 8-4 and the lift cylinder 9 can be any appropriate cylinders known to the art.

Since the front carrying arm 8-2-4 and the rear carrying arm 8-3-4 can rotate and the rear carrying arm assembly can be translated, it is not necessary for a position of a container lorry under inspection stopping at the entrance of the scanning passage to be very accurate, but the trailer itself looks for and determines a position of a wheel of the container lorry stopping at the entrance. Therefore, accuracy with which a driver stops a container lorry can be lower and operation time of the trailer system for scanning each vehicle can decrease. In addition, a scanning cycle process can be simplified and the trailer can be applied to different diameters of wheels of vehicles under inspection so as to enlarge applicable range of the system. Furthermore, since the lift cylinder 9 is used, it is not necessary for a container lorry to be driven onto or away from the trailers so that there is no risk for a chassis of the vehicle to be scraped. As a result, the system is safe and reliable.

The self-driving trailer system according to the present invention is also provided with a self-balancing system. With the balancing system, frictional force between the trailers 1 and 2 and the rails 3 increases so that weight of the trailers can decrease. The balance wheels 10 on the trailers, and the front carrying arm and the rear carrying arm are disposed on both sides of the running wheels 6. In operation, the balance wheels 10 roll along the respective groove-shaped tracks fixed to the foundation for the system. The balance wheels 10 are used to balance the trailer subjected to overturning moment generated by weight of the container lorry under inspection and the trailers in operation. In addition, normal force applied by the running wheels 6 of the trailers to the rails 3 increases because of the groove-shaped tracks fixed to the foundation so that the frictional force between the running wheels and the rails increases. As a result, an available power of the driving devices of the trailers increases so as to avoid adding weight to the trailers for improving the frictional force, and so as to decrease total weight of the trailer system.

After the scanning is completed, the trailers and the container lorry stop at the exit of the scanning passage. The lift cylinder 9 drives the carrying device 8 to move downwards along the trailer body slide grooves 7-1 and 7-2 disposed in the trailer body 7 so that the front wheels of the container lorry moves downwards onto the ground. Then, the cylinders 8-2-1 and 8-3-1 drive the front carrying arm 8-2-4 and the rear carrying arm 8-3-4 to rotate so that the front carrying arm 8-2-4 and the rear carrying arm 8-3-4 are positioned parallel to the passage or the trailer. The container lorry runs away from the scanning passage.

After the front wheels of the container lorry moves downwards onto the ground, and the front carrying arm 8-2-4 and the rear carrying arm 8-3-4 are positioned parallel to the passage or the trailer, the driving device 5 drives the trailer to run towards the entrance of the passage. In a predetermined position of the system, it is automatically detected by a sensor whether the container lorry has left the passage. After it is determined that the container lorry has left the passage, the cylinder 8-2-1 drives the front carrying arm 8-2-4 to rotate by 90 degrees so that the front carrying arm is positioned perpendicular to the passage or the trailer body, and at the same time the trailer continues the movement towards the entrance of the passage. When the front carrying arm 8-2-4 touches a front wheel of another container lorry, the sensor 8-2-5 sends a control signal to stop the trailer. Up to now, a complete scanning inspection is finished. The system begins the next scanning cycle.

In addition, the trailer system according to the present invention can be used to pull a container lorry to pass through a scanning passage, and to pull other objects rather than the container lorry for other systems rather than the scanning inspection system. In addition, the present trailer system can use only one trailer rather than two trailers to pull one front wheel of a container lorry in order to achieve the scanning inspection. Therefore, the trailer system can use one trailer.

Although the embodiments of the self-driving trailer system for inspecting a vehicle by radiation-imaging the vehicle and the inspection method by radiation imaging of a vehicle are described, it will be appreciated by those skilled in the art that the trailer system can be applied to other fields to transport vehicles and goods. Therefore, it will be appreciated by those skilled in the art that modifications and applications may be made in these embodiments without departing from the principles and spirit of the general inventive concept, the scope of which is defined in the appended claims and their equivalents.

Therefore, although the above trailer system is applied to the radiation imaging of vehicles, it can be used to transport vehicles and goods for other purposes except the radiation imaging inspection.

In addition, the above trailer system may be provided with one trailer, at least one pair of trailers, or a plurality of trailers.

Although the running wheels run on the rails, the running wheels can runs on other road surfaces or surfaces.

Although the cylinders are used in the trailer system, other driving devices known to the art can be used.

Although the above trailer system is provided with the trailers that reciprocate, it can be provided with a plurality of trailers that run circularly.

Although the rotation range of the front carrying arm and the rear carrying arm is 90 degrees in the above embodiments, the front carrying arm and the rear carrying arm can rotate by any appropriate angles such as an angle of 90 or 120 degrees.

Although the rear carrying arm assembly and the carrying device move along the slide grooves in the above embodiments, the present invention is not limited thereto. For example, the rear carrying arm assembly and the carrying device can move along guides such as tracks and guide rods. 

1. A trailer system comprising: two trailers disposed opposite to each other, each of the two trailers comprising: a trailer body; and a carrying device disposed on a side of the trailer body facing a region between the two trailers for lifting and lowering an object and supporting the object during carrying the object by the trailer.
 2. The trailer system according to claim 1, wherein each of the trailers further comprises a balancing device disposed on the other side of the trailer opposite to the side to keep balance of the trailer body when the carrying device lifts and lowers the object and the object is carried.
 3. The trailer system according to claim 2, wherein the balancing device comprises a balance wheel rotatably connected to the trailer body, and the trailer system further comprises a groove-shaped track adapted to guide the balance wheel, wherein the trailer body being balanced by contact between the balance wheel and the groove-shaped track.
 4. The trailer system according to claim 1, wherein each of the trailers further comprises: running wheels mounted to the trailer body so that the trailer body is movable; and a driving device coupled to the trailer body to drive the running wheels to rotate.
 5. The trailer system according to claim 4, wherein each of the trailers further comprises: a first pair of guide wheels and a second pair of guide wheels respectively disposed at a front end and a rear end of the trailer body to guide the trailer when the trailer runs, wherein the running wheels run on a rail located between the first pair of guide wheels and between the second pair of wheels.
 6. The trailer system according to claim 1, wherein the carrying device comprises: a base connected with the trailer body to be movable upwards and downwards; and a front carrying arm assembly and a rear carrying arm assembly respectively coupled with the base to support the object during lifting and lowering the object and carrying the object, wherein the rear carrying arm assembly is substantially horizontally movably connected with the base.
 7. The trailer system according to claim 6, wherein the front carrying arm assembly comprises: a base portion coupled with the base; a front carrying arm rotatably connected with the base portion; a rotary arm fixed to the front carrying arm to be rotatable about an axis together with the front carrying arm; a cylinder has a piston rod and a cylinder respectively hingedly connected to the rotary arm and the base to drive the rotary arm to rotate so that the rotary arm drives the front arm to rotate between a spread position and a retracted position.
 8. The trailer system according to claim 7, wherein the front carrying arm assembly further comprises a sensor coupled with the front carrying arm to detect whether the front carrying arm touches an object.
 9. The trailer system according to claim 8, wherein the rear carrying arm assembly comprises: a base portion movably coupled with the base; a rear carrying arm rotatably connected with the base portion of the rear carrying arm assembly; a rotary arm fixed to the rear carrying arm to be rotatable about an axis together with the rear carrying arm; a cylinder has a piston rod and a cylinder respectively hingedly connected to the rotary arm of the rear carrying arm assembly and the base of the rear carrying arm assembly to drive the rotary arm of the rear carrying arm assembly to rotate so that the rotary arm of the rear carrying arm assembly drives the rear arm to rotate between a spread position and a retracted position.
 10. The trailer system according to claim 9, wherein each of the trailers further comprises a rear carrying arm assembly moving cylinder for substantially horizontally moving the rear carrying arm assembly, and two base slide grooves disposed in the base of the carrying device, the rear carrying arm assembly being substantially horizontally movable along the base slide grooves by the rear carrying arm assembly moving cylinder.
 11. The trailer system according to any one of claim 6 wherein each of the trailers further comprises two trailer body slide grooves disposed in the trailer body, wherein the carrying device can be lifted and lowered along the trailer body slide grooves by a lift cylinder.
 12. The trailer system according to claim 11 wherein the carrying device further comprises two sliders corresponding to the two trailer body slider grooves, the carrying device being movable upwards and downwards in such a manner that the two sliders are positioned in the two trailer body slider grooves, respectively, wherein engagement of one of the two sliders and one of the two trailer body slide grooves can constrain swings of the carrying device around a first axis parallel to a moving direction of the trailer and around a second axis which is perpendicular to the first axis and which is vertical during upward and downward movement of the carrying device, and engagement of the other slider and the other slide groove can constrain swing of the carrying device around a third axis which is perpendicular to the first axis and the second axis and which is horizontal during upward and downward movement of the carrying device.
 13. The trailer system according to claim 9 wherein the front carrying arm of the front carrying arm assembly and the rear carrying arm of the rear carrying arm assembly are disposed on a side of the running wheels, and the balance wheel are disposed on the other side of the running wheel opposite to the side of the running wheels.
 14. The trailer system according to claim 13 further comprising running rails on which the trailers run, cable drag chains for dragging electrical cables, a controller for control operation of the trailer system, and a concrete foundation on which the running rails fixed.
 15. The trailer system according to claim 14, wherein each of the trailers further comprises a rear carrying arm assembly moving cylinder for substantially horizontally moving the rear carrying arm assembly, and two base slide grooves disposed in the base of the carrying device, the rear carrying arm assembly being substantially horizontally movable along the base slide grooves by the rear carrying arm assembly moving cylinder.
 16. The trailer system according to claim 15 wherein each of the trailers further comprises two trailer body slide grooves disposed in the trailer body, wherein the carrying device can be lifted and lowered along the trailer body slide grooves by a lift cylinder.
 17. The trailer system according to claim 14 wherein the groove-shaped tracks are disposed in the concrete foundation, the balancing wheels can be fitted in the corresponding groove-shaped tracks fixed to the concrete foundation, and can roll along the corresponding groove-shaped tracks.
 18. The trailer system according to claim 1 wherein the object comprises a vehicle, and the trailer system is used in an inspection system for inspecting the vehicle by radiation imaging of the vehicle.
 19. The trailer system according to claim 18 wherein when the trailer system operates, the front carrying arm is spread, and the trailer moves towards the vehicle under inspection; and when the front carrying arm touches a front wheel of the vehicle under inspection, the sensor sends out a signal so that the trailer stops and an addressing action is completed.
 20. The trailer system according to claim 18 wherein each of the trailers further comprises a rear carrying arm assembly moving cylinder for substantially horizontally moving the rear carrying arm assembly, wherein when the trailer system operates, the front carrying arm is spread, and the trailer moves towards the vehicle under inspection; when the front carrying arm touches a front wheel of the vehicle under inspection, the sensor sends a signal so that the trailer stops and an addressing action is completed; and then the rear carrying arm is spread, and the rear carrying arm assembly is substantially horizontally moved by the rear carrying arm assembly moving cylinder so that the front carrying arm and the rear carrying arm clamp the front wheel.
 21. The trailer system according to claim 20, wherein each of the trailers further comprises two base slide grooves disposed in the base of the carrying device, the rear carrying arm assembly being substantially horizontally movable along the base slide grooves by moving of a piston rod of the rear carrying arm assembly moving cylinder.
 22. The trailer system according to claim 20, wherein the trailer system automatically judges whether the front carrying arm and the rear carrying arm have already clamped the front wheel of the container lorry at a predetermined clamping force by setting an operation pressure of the rear carrying arm assembly moving cylinder; and if the system determines that the front carrying arm and the rear carrying arm have already clamped the front wheel at the predetermined clamping force, the system sends out a signal to stop movement of the piston rod of the rear carrying arm assembly moving cylinder, and the trailer continues the following operations.
 23. The trailer system according to claim 22 wherein each of the trailers further comprises two trailer body slide grooves disposed in the trailer body, wherein the carrying device can be lifted along the trailer body slide grooves by a lift cylinder, so that the front wheels of the vehicle can be spaced apart from the ground and the vehicle can be pulled by the driving device to move through a scanning passage of the inspection system for scanning the vehicle.
 24. The trailer system according to claim 23 wherein after the scanning has been completed, the trailers and the vehicle stop at an exit of the scanning passage, and the carrying device can be lowered along the trailer body slide grooves by the lift cylinder so that the vehicle moves downwards to the ground; and then the front carrying arm and the rear carrying arm rotate to retracted position, and the vehicle leaves the scanning passage.
 25. The trailer system according to claim 24 wherein while the vehicle is moving away from the scanning passage, the driving device drives the trailer to move towards the entrance of the scanning passage; after it is determined that the vehicle has left the scanning passage, the cylinder of the front carrying arm assembly drives the front carrying arm to be spread while the trailer is moving towards the entrance of the scanning passage; and when the front carrying arm touches a front wheel of another vehicle under inspection, the sensor sends a control signal to stop the trailer so that a complete scanning inspection process is finished.
 26. A method for inspecting a vehicle by radiation imaging of a vehicle in a scanning passage through a trailer system, the trailer system comprising two trailers disposed opposite to each other, each of the two trailers comprising a trailer body; and a carrying device disposed on a side of the trailer body facing a region between the two trailers for lifting and lowering a front wheel of the vehicle and supporting the front wheel during carrying the vehicle by the two trailers, the method comprising steps of: lifting the front wheels of the vehicle under inspection by means of the carrying devices of the two trailers, and inspecting the vehicle by radiation scanning of the vehicle while the two trailers move.
 27. The method according to claim 26, wherein prior to the lifting the front wheels of a vehicle, the method further comprises steps of: spreading a front carrying arm of the carrying device of each of the two trailers; moving the trailers and thus the front carrying arms towards the vehicle under inspection, and stopping the trailers when the respective front carrying arms touch the corresponding fronts wheels of the vehicle under inspection; spreading a rear caring arm of the carrying device of each of the two trailers, and horizontally moving the rear carrying arms so that the front carrying arms and the rear carrying arms abut against the corresponding front wheels of the vehicle under inspection.
 28. The method according to claim 27, further comprising: lowering the carrying devices so that the vehicle moves downwards to the ground, after the scanning is completed; and retracting the front carrying arms and the rear carrying arms, and driving the vehicle away from the scanning passage.
 29. The method according to claim 28, further comprising: moving the trailers toward an entrance of the scanning passage after retracting the front carrying arms and the rear carrying arms.
 30. The method according to claim 28, further comprising: spreading the front carrying arms after determining that the vehicle has left the passage, while the trailers are moving towards the entrance of the scanning passage.
 31. The method according to claim 30, further comprising: stopping the trailers when the respective front carrying arms touch corresponding fronts wheels of another vehicle under inspection.
 32. A trailer system comprising: a trailer, the trailer comprising: a trailer body; and a carrying device disposed on a side of the trailer body for lifting and lowering an object and supporting the object during carrying the object by the trailer. 